Pence has been the governor of Indiana since 2013. According to Reuters, he had a midday deadline Friday to declare if he would run for another term as governor, which meant Trump had to make his pick by that time.

"Honored to join @realDonaldTrump and work to make America great again," Pence tweeted shortly after.

Sources had leaked that Pence was Trump's top choice Thursday, but the campaign did not confirm it until Friday. Trump had also been considering former Speaker of the House Newt Gingrich and New Jersey Gov. Chris Christie.